A piece of advice I once received: Don’t ever talk about your period at work. No one wants to know.

I have broken that rule. Menstrual cycles are fascinating, and at the risk of a major breach of workplace etiquette, here’s why we should all be talking about them more: If you’re a woman, your cycle shapes your physiology more than you probably realize, with hormones orchestrating a monthly chemical waltz through your brain and metabolism. And men, it wouldn’t kill you to understand more about ...